The problem with reddit mods is that it's like the cops: the people least suited to the job are the ones who are most attracted to it. We end up with subs that effectively have no rules except the random whims of the mods and reddit themselves don't care at all. The comments on reddit reflect this perfectly because it's become more toxic over time, a haven for people interested in the casual abuse of others.
I'd say one difference between reddit mods and the police is that the stakes are really low on reddit.
Arguing or getting upset about mod decisions gives off strong "fight with the bouncer" vibes. Even if you're right, there's no way to "win". The best course of action is to just quietly move on.